Automatic chain changing apparatus for flat knitting machines,preferably raschel warp knitting machines



May 27, 1969 SCHMID R. AUTOMATIC CHAIN CHANGING APPARATUS FOR FLATKNITTING MACHINES, PREFERABLY RASCHE Filed Dec. 20, 1966 III! L WARPKNITTING MACHINES Sheet of 5 //VVENTOR:

RE/NHOLD SCH/W0 ATTORNEy 5.

R. SCHMID CHANGING APPARATUS FOR FL RABLY RASCHEL WARP KNITTI IN EFE May27, 1969 TOMATIC CHA ACHINES PR AT KNITTING NG MACHINES Sheet 2 of 5Filed Dec. 20, 1966 J //vv/v TOR:

REl/VHOLD SC/vN/D O 4IQ\ ATTORNEYS May 27, 1969 R. SCHMID 3 3 AUTOMATICCHAIN CHANGING APPARATUS FOR FLAT KNITTING MACHINES, PREFERABLY RASCHELWARP KNITTING MACHINES Filed Dec. 20, 1966 Sheet 3 of 5 //v isa/70R:-

REM/HOLD 50mm 89 ATTORNEYS May 27, 1969 AUTOMATIC CHAIN CHAN MACHINES,PREFERABLY RA Filed Dec. 20, 1966 R. SCHMID 3,446,039 GING APPARATUS FORFLAT KNITTING SCHEL WARP KNITTING MACHINES Sheet 4 of5 A TTOR NEVS y 7,1969 R. SCHMID 3,446,039

AUTOMATIC CHAIN CHANGING APPARATUS FOR FLAT KNITTING MACHINES,PREFERABLY RASCHEL WARP KNITTING MACHINES Filed Dec. 20, 1966 Sheet 5 of5 uwm vro/z. RNA/HOLD saw/0 A TTOR/VB S United States Patent ClaimsClaims ABSTRACT OF THE DISCLOSURE This invention provides an automaticchain changing apparatus for flat knitting machines. The apparatusincludes means for guiding a main pattern chain having individualtrack's over a main pattern chain drum.,A control chain havingindividual tracks is guided over a control chain drum. A shifting leverconstruction which provides a multi-part shifting lever adjacent each ofthe said chain operates in conjunction with a striker bar to transmitthe desired movement to a single layering rail on the said knittingmachine.

Background of the invention This invention relates to an automatic chainchanging apparatus for flat knitting machines with shifting levers fortracing through a roller the individual tracks of a main and patternchain guided over a chain drum, whereas a control chain is guided overanother drum.

Pattern changing apparatuses for flat knitting machines, preferablyRaschel warp knitting machines, are known. They are employed in theproduction of single and double-section knitwear.

On an upper chain drum, as a rule, up to three chain link rows(patterns) ,can be placed side by side for one layering rail andselectively traced by a roller for obtaining the desired shiftingmovement of the rows of eyepointed needles. Moreover, it is possible toeffect the change of pattern for all layering rails simultaneously orfor each individual rail alone.

The change of pattern is initiated by a lower drum which, during thecontrol operation, is automatically stepped on by one chain link. Bydifferent heights of the chain links a lateral shifting of the so-calledside bars with their rollers is achieved. The shifting of the side barsand thus the change-over of the rollers to another chain link track canbe effected only when the entire set of layering rails has beenpreviously pushed off from the side bars. By the pushing off of thelayering rails the side bars are relieved from the spring pull of thereset device for the layering rails.

Consequently, after the last mesh of a knitting pattern has been formed,the entire set of layering rails is to be lifted according to thehighest chain link positioned before the rollers so that the rollers canbe changed over to a neighboring track. Furthermore, for the purpose ofshifting the side bars it is necessary to engage the lower drum and tostep it on by one chain link.

Subsequently, the layering rails are reset so that the rollers of theside bars rest on the selected chain link track so as to benonpositively connected therewith.

If, for example, a side bar rests on a high chain link during thecontrol operation and if, according to the pattern, this side bar is totrace with its roller the neighboring chain link track having a lowerlink, the layering rail, for the purpose of lifting, has first to bepushed off in one direction, e.g. to the left, and subsequently to bemoved back further to the right relative to its original position. Thetotal lift for the layering rails involved therein often amounts to asmuch as 5 cm.

On principle, all layering rails have to take part in the pushing-offoperation, no matter whether their side bars are to be changed over toanother chain link track or not. The stroke of the pushing-off movementis invariable for all places where a change of pattern is carried outand cannot be adapted to the heights of the chain links of eachindividual change pattern. Thus it happens that the rollers are liftedby a great distance and that all layering rails are thereby shifted inthe longitudinal direction of the machine, whereas according to thepattern a small amount of the stroke of the pushing-off movement wouldbe sufficient at this place where the change is effected.

The pushing off of the layering rails can be initiated not before thelatch needle which is in a high position drops and projects with itsneedle hook out of the row of eye-pointed needles. The entirechange-over operation has to be terminated at the latest whenthe'underlaying is commenced. This operation would have to be carriedout within the shortest period of time. However, the necessaryconsiderable displacement of the mass of the entire set of layeringrails during the pushing-off operation and the possible loosening of thewarps through the often considerable lift of the layering rails do notpermit of high working speeds.

Summary of-the invention It is the object of the present invention toeliminate the aforementioned drawbacks and to permit of a speed ofproduction which is many times higher. By a suitable arrangement of thecontrol mechanisms it is intended to dispense with the pushing off ofthe entire set of layering rails. The control time thus won can beutilized in an advantageous manner for the changingover operation.Moreover, during the changing-over operation only those layering railsare moved which are meant to work subsequently on another neighboringchain link track by their operating mechanisms.

A mass equilibrium in the movement of the layering rails during thecontrol operation is achieved in that the necessary movement of thelayering rails during the control operation is oppositely oriented inmany cases. All rails which are changed over from a high link to a lowchain link have the same directions of movement, whereas vice versa therails to be moved simultaneously for the change over from a low chainlink to a high chain link have reverse directions of movement.

According to the invention, an automatic chain changing apparatus forflat knitting machines comprises a main and pattern chain havingindividual tracks, a chain drum over which said main and pattern chainis guided, a control chain, another drum for guiding said control chainthereon, multipart shifting levers each having a fulcrum and a lowerjoint, a roller associated with each of said shifting levers, saidshifting levers serving for tracing the individual tracks of said mainand pattern chain by means of said roller, single transmission means,jointed connecting means connecting a plurality of said shifting leversjointly to said transmission means, a single push rod and a singlelayering rail associated with said transmission means, and a striker barfixed to the frame of the apparatus, said shifting levers beingselectively connectible, in accordance with said control chain, withsaid striker bar in the vicinity of said lower joint of said shiftinglevers.

By the invention the control stroke is made variable even for eachindividual layering rail and the length of the control stroke can beadjusted according to the pattern for each place where a change iseffected.

Furthermore, a speeding up of the change-over operation is achieved inthat during the control operation no great distances have to be overcomeat the control chain of the lower drum. The necessary lift during thecontrol operation is produced by four chain links with the lower drumworking, as usual, at a speed of one chain link per row of meshes. Alarge amount of the rotary movement of the drum necessary for thecontrol operation can be determined by anticipatory control, i.e. priorto the commencement of the control operation proper the lower drum canbe engaged while the layering rails are still performing their shiftingmovements. The control operation is prepared already four rows beforethe change of pattern takes place.

Brief description of drawings One embodiment of the invention will nowbe described by way of example and with reference to the accompanyingdrawings, in which:

FIG. 1 is a longitudinal section through an apparatus according to theinvention;

FIG. 2 is a partial view, on an enlarged scale, of the control andtransmission elements;

FIG. 3 is a section through the upper transmission elements;

FIG. 4 is a top plan view of the gear showing the arrangement of therams;

FIG. 5 is a section through the gear lever having a double link and thecontact elements thereof, and

FIG. 6 is a side view of a disengageable arrangement of leversassociated with the lower drum.

Description of specifi embodiment FIG. 1 shows a chain changing devicein which a camshaft 1 drives through a chain drive 2 a worm shaft 3 andthereby an upper chain drum 4 through a shaft 5 thereof in a usualmanner synchronously with the working of the knitting tools of a fiatknitting machine. Depending on whether single or double-section knitwearis to be produced, a main and pattern chain 6 is stepped on by two or byfour chain links per turn of the eccentric shaft. The necessary changein transmission can be effected at a sprocket wheel 7 which is arrangedin overhung position. The main and pattern chain 6 is traced by a roller8 (FIGS. 1 and 2) which is fixed to a lever 9 serving as a rollercarrier. The lever 9 is pivotable about a fulcrum 10 associated with adouble link 11. A lower joint 12 of the double link 11 can be pressed bya lever 13 against a striker bar 14 so as to be nonpositively connectedtherewith.

During this pressing operation a shifting movement is transmitted in thedirection of double arrow to a layering rail 21 through the intermediaryof the roller 8, the lever 9, the fulcrum 10, the double link 11, allacting as transmission elements, a link 15, a clamping piece 16, a ram17 with toothed wheels 62, 63, 64 and 65 (FIG. 3), a ram 55 with aconnecting piece 18 and a push rod 19. A spring 22 provides thenecessary non-positive connection between the roller 8 and the main andcontrol chain 6, whereas a spring element 23 acts to retain the push rod19 in ball cups 42 (FIG. 4). The push rod 19 permits of transverseoscillation of the layering rail 21 perpendicular to the drawing planewhich, just as the shifting movement, is necessary for the purpose offorming meshes.

From the camshaft 1 (FIG. 1) rotary motion is transmitted throughanother chain drive 24 to a positively connected pin clutch 25.

A lower worm shaft 26 is engaged only when a magnet 27 receives anelectric impulse from an information carrier. This causes a contactpiece 28 to be removed from the radial orbit of a cam 29 on the pinclutch and the lower worm shaft 26 to be engaged by means of the pinclutch 25. The control from the magnet 27 is such that the lower wormshaft 26 can turn round only once per control impulse since a returnspring 30 brings the contact piece 28 into the radial orbit of the cam29 immediately after the magnet 27 releases. Thereby disengagement ofthe lower worm shaft 26 is effected. The transmission of a worm 31relative to a worm wheel 32 is such that a lower drum 33 is stepped onby several, e.g. four, chain links per turn of the Worm shaft and thencomes to a standstill by a self-locking action of the worm gear or othermeans, e.g. a brake. In accordance with an impulse, which may also beeffected in a purely mechanical manner, the lower drum 33 is thus turnedby steps and 'a control chain 34 is moved on by several links likewisein stepby-step fashion.

FIGS. 1 and 2 show that a roller 35 which is secured to a lever 36 canexert a lifting movement on lever shears 37 by the agency of the controlchain 34. The movement of the lever shears 37 is, in turn, transmittedto the lever 13. Through the joint 12 the lever 13 is connected with thedouble link 11 and, according to the height of the chain links of thecontrol chain 34, locking of the series of levers 36, 37, 13 is causedin such a manner that the joint 12 is arranged at an invariable distancefrom the striker bar 14 which is fixed to the frame of the apparatus.

An axle 38 constitutes a fulcrum for the lever 13, which fulcrum isfixed to the frame. The same applies to an axle 39 with respect to thelever 36. The axle 39 can be removed from its bearings and pivoted whenthe control chain 34 is to be placed on to the drum 33. This operationwill be explained in detail hereinafter.

It is now possible to transform the lift of the roller 8 to the layeringrail 21. The lever shears 37 having springs 40 and 41 compensate anymanufacturing tolerances as to the height of the links of the controlchain 34 and they thus guarantee that the lever 13 engages the strikerbar 14 so as to be free from play.

A lever system is provided for each chain link track of the main andpattern chain 6 as well as of the control chain 34 (FIGS. 1 and 2).Moreover, several chain link tracks are provided for each layering rail.In the embodiment described, three tracks are provided for each layeringrail (FIGS. 3 and 4). According to the number of layering rails, FIG. 4shows ball cups 42, 43, 44, 45, 46 and 47 which serve to receive therespective push rod 19 and thus transfer the shifting movement to thelayering rails. The ball cups are received in respective connectingpieces 48, 18, 50, 51, 52 and 53 (FIGS. 3 and 4). The connecting piecesare connected with rams 54, 55, 56, 57, 58 and 59, respectively.

The layering rails are arranged closely side by side within the machine.This is desirable in order to keep the oscillatory movements across thelatch-needle section as small as possible. Furthermore, it is necessaryto pass on the required shifting movement by means of the push rods 19,if possible with a central push, in the direction of the longitudinalaxis of the layering rails. That is why the ball cups 42 to 47, too,have to be arranged closely side by side.

According to the object of the invention, several chain link tracks areto be provided for each of the layering rails arranged closely side byside. In the illustrated embodiment, at least three chain link tracksare provided for each layering rail. This results in a large overall'width of the drums 4 and 33.

From the respective outer tracing points of the rollers 8, therefore,transmission means have to be provided in order to ensure that theshifting movement is transmitted from the respective outer chain linktrack into the planes of the outer ball cups 42 and 47. This ispreferably effected through a rolling coupling. For this purpose,according to FIGS. 3 and 4, separate rams 17 and 61 are arranged in therespective center planes of the three outer chain link tracks, said ramscarrying rack profiles on their undersides. The translatory movement istransmitted from the ram 17 to the ram 55 and from the ram 61 to the ram58 through the toothed wheels 62 and 63 and 64 and 65, respectively,through the intermediary of shafts 66 and 67.

As shown in FIGS. 3 and 4, each ram 17 has, through links 15, 68 and 69and by means of the clamping piece 16, three single levers 9, 70 and 71connected thereto which, together with the series of levers 9 to 11linked thereto, permit three chain link tracks to be traced. In thiscase it is only admissible that the lever 9 takes charge of atransmission of movement from the main and pattern chain 6 to the ram17. The respective levers 70 and 71 (FIG. 4) join in the movement of theram 17 but are unable to transmit forces since their fulcrumscorresponding to'the joint 12 are not non-positively connected with thestriker bar 14. This situation is illustrated in FIG. 2 in which aseries of levers adjacent to the series of levers 9, 11, 13-, 37 and 36is shown in dot-and-dash lines in disengaged position.

A roller 73 bears against a so-called zero link on a chain track 72illustrated in dot-and-dash line which belongs to the control chain 34.This roller 73 is mounted in a lever 74 which through lever shears 75pulls a lever 76 which is linked to the lever shears 75 into theposition shown in dot-and-dash lines in such a manner that a stop member77 on the lever 76 is arranged at a distance from the striker bar 14which is fixed to the frame. A lever 78 adjacent to the transmissionelements consisting of the lever 9, the fulcrum and the double link 11is swung out of its position by its fulcrum 79 to such an extent that aroller 80 is removed from the chain track. This is also the case whenthe clamping piece 16 through the link 15 changes the position of theparts 11, 10, 9 etc. according to the pattern by means of the main andpattern chain 6 through the roller 8.

As already mentioned, provision is made that the disengaged transmissionlevers attached to the clamping piece 16 through the links 15, 69 doesnot influence the chain tracing operation of the engaged transmissionlever connected by the link 68 even if said engaged transmission leverrests with its roller on a zero link of the main and pattern chain 6 andeven if the neighboring chain link tracks have the highest chain link inthe same row, said chain link corresponding to the width of the traversemotion of the layering rails.

Accordingly, the distances between the disengaged transmission levelsand the striker bar 14 have to be provided according to the highestchain link for the disengaged transmission levers. Such distances mayamount to as much as 70 mm. and more and depend on the width of thetraverse motion of the knitting machine, said width being determined bythe construction of the knitting machine. The engagement of therespective transmission levers, 1'.e. the non-positive connection withthe striker bar 14 through the control chain 34, cannot be effected, asis required, in a split second since the control paths are very long.

Therefore, according to another feature of the invention, the disengagedtransmission levers are pivoted, already several rows before theintended change of pattern, towards the striker bar 14 to such an extentthat the clearance between the roller of the lever system to be engagedand the chain link track thereof is not greater than the height of onechain link at the most.

With a maximum difference in height of facing chain links in the twopattern tracks it is sufficient for the disengaged lever system to pivotthe lever 76 with its stop member 77 relative to the striker -bar 14which is fixed to the frame by a distance which corresponds to doublethe difference in height of the chain links. A precondition is, however,that a transmission ratio of 2:1 exists between the lift of the roller 8and the movement of the layering rail in the direction of the doublearrow 20, as in the casein the embodiment described. Furthermore, when,four rows before the intended change of the pattern or track, theworking chain link track has the link heightsl'2-8-12-6 and when in thecorresponding rows the chain link track selected to be traced after thechange has the link heights-18-14-l0-8, the lever 76 can be returned bythe control chain 34 (FIG. 2) during the anticipatory control from itsswung-out position relative to the striker bar 14, the return movementbeing effected through the lever shears 75 and the lever 74. In theembodiment described, the lever 76 can be returned from double the linkheight of 22 to double the link height of 20 in the first row, in thesecond row from 20 to 16 and in the third row from 16 to 12, in eachcase again by double the height. In the fourth row to be operated thelever 76 is finally non-positively connected with the striker bar 14.

During the control operation the layering rail to be moved is shiftedfrom a link height 6 to a link height 8 where the new pattern begins.

The chain link of the control chain 34 positioned in the fourth row,which link is associated with the engaged series of levers, has alreadyreleased the roller 35 during the change-over operation whereby thelever 13 with its joint 12 can freely pivot relative to the striker bar14.

The control movement of the transmission means (anticipatory control)carried out up to the third row is effected without loading by thelayering rail or the spring 22 thereof. Therefore, in the control chain34 even greater shifting distances can be covered than are present inthe pattern chain 6. Owing to the slight movement of masses the maximumspeed of the machine is not impaired by this control operation. Saidspeed only depends on the distance to be covered during the shiftingoperation in the pattern chain.

If, due to the main and pattern chain 6, the situation in the controlrow (fourth row) is such that the layering rail has to be returned froma higher chain link to a lower one of the neighboring chain link trackto be engaged for tracing, the roller 8 is e.g. pressed by means of aspring 81 against the pattern track of the main and pattern chain 6 tobe engaged as shown in FIG. 5, whereas the lever 13 by the control chain34 has non-positively locked the double link 11 relative to the strikerbar 14 through the joint 12.

When through the operation serving the purpose of control through thecontrol chain 34 the engaged series of levers is relieved from load, thespring tension of the spring 22 at this moment becomes effective throughthe rams, the clamping pieces and the links up to the fulcrum 10. Underthe action of this force the lever 9 serving as roller carrier ispivoted clockwise about the fulcrum 10, the spring 81 which is verysmall in comparison with the spring 22 is compressed and a stop plate 82of the lever 9 comes into contact with a damping element 83 which issituated between the double link 11. Subsequently the shifting movementcan be traced from the engaged chain track.

FIG. 5 further shows a stop pin 84 which limits the travel of the spring81 by a slot 85 in the double link 11.

FIG. 6 shows how the axle 38 on which the lever 36 is mounted can bepivoted through a disengaging lever 86. This is necessary in order to beable to place the control chain 34 on to the lower drum 33 withouthaving to relieve the spring 22. When the series of levers 15, 9, 11,13, 37 and 36 is in disengaged position, the action of the spring 22 issuch that the roller 35 is pressed against the lower drum 33. Thedisengaging lever 86 keyed to the axle 38 can be pivoted by turning theaxle 38 by means of a hand lever 87. The lever system consisting of thelever 36 and the disengaging lever 86 then assumes the positionindicated in dot-and-dash lines in FIG. 6. In this position the lever 36serving as a carrier for the roller 35 has withdrawn the latter from thelower drum 33 to such an extent that it is possible to place the controlchain 34 thereon.

The invention may be embodied in other specific forms without departingfrom the spirit or essential characteristics thereof. The presentembodiment is therefore to be considered in all respects as illustrativeand not restrictive, the scope of the invention being inidcated by theappended claims rather than by the foregoing description and all changeswhich come within the meaning and range of equivalency of the claims aretherefore intended to be embraced therein.

I claim:

1. An automatic chain changing apparatus for flat knitting machines,comprising,

(a) means guiding a main pattern chain having individual tracks over amain pattern chain drum,

(1)) means guiding a control chain having individual tracks over acontrol chain drum,

() means mounting a multi-part shifting lever adjacent each said chain,

(d) said lever adjacent said main pattern chain having a fulcrum locatedat a lower joint,

1(e) means connecting said shifting levers to form an interactingshifting lever construction,

(f) means mounting a roller on each said shifting lever to trace theindividual tracks of said main pattern chain and said control chain,

(g) jointed means connecting a plurality of said shifting leverconstructions to a single transmission means for transmitting movementto a single push rod and a single layering rail,

(h) a striker bar fixedly mounted to the frame of the apparatus, and

(i) means driving said control chain to actuate a said adjacent shiftinglever to cause the lower joints of said shifting levers adjacent saidmain pattern chain to selectively contact said striker bar.

2. A automatic chain changing apparatus as claimed in claim 1, whereinthe fulcrum of each shifting lever is located above the rollers.

3. An automatic chain changing apparatus as claimed in claim 1, whereinthe fulcrum of each shifting lever is located below the rollers.

4. An automatic chain changing apparatus as claimed in claim 1 whereinthe shifting levers adjacent said main pattern chains are non-positivelyconnectible with the striker bar.

5. An automatic chain changing apparatus as claimed in claim 1 whereinthe shifting levers adjacent said main pattern chains are positivelyconnectible with the striker bar.

6. An automatic chain changing apparatus as claimed in claim 1, whereindamping means are provided on the shifting levers.

7. An automatic chain changing apparatus as claimed in claim 6, whereinsaid shifting lever connecting means include control levers pivoted tothe lower joints of the shifting levers and spring elements interposedbetween the control levers, said control levers being constructed insuch a manner that due to the provision of the interposed springelements they are able to elminate the tolerances of the link heights ofthe control chain.

8. An automatic chain changing apparatus as claimed in claim 7, whereinsaid shifting lever connecting means includes a series of control leverspivoted to the shifting levers and two fulcrums which are fixed to theframe of the apparatus and situated below the joint common to theshifting levers and the control levers, and a disengaging lever isprovided for pivoting one of the fulcrums fixed to the frame out of itsarrested operative position in such a manner that the distance betweenthe roller and the periphery of the lower chain drum increases, whichdisengaging lever is pivotally mounted in the other stationary fulcrumof the series of control levers.

9. An automatic chain changing apparatus as claimed in claim 8, whereina stop plate and a damping element are provided on the shifting leversand the shifting levers next to the respective shifting levers which arearrested by the striker bar are capable of changing the position oftheir lower joint during the shifting movement of the layering railsrelative to the striker bar fixed to the frame in accordance with theintermittently driven control chain in such a manner that the rollergets into contact with its associated chain link track of the main andpattern chain and wherein a small air gap remains between the stop plateand the damping element before the shifting lever arrested by thestriker bar through the series of control levers is disengaged from thestriker bar by means of the control chain.

10. An automatic chain changing apparatus as claimed in claim 9, whereinthe shifting movement of the outer layering rails is realizable througha push rod arranged substantially parallel to the longitudinal axis ofthe layering rails and wherein ball cups of said push rod are arrangedoutside the machine frame and can be driven by means of two rams guidedparallel to each other and toothed wheels and a shaft are provided, saidrams being connected with the toothed wheels which are mounted on saidshaft.

References Cited UNITED STATES PATENTS 2,106,434 1/1938 Morton et al6686 3,145,549 8/1964 Siccardi 66-84 3,350,901 11/1967 Noe 66-86 FOREIGNPATENTS 30,867 10/ 1926 France. 275,451 6/1914 Germany. 259,027 10/ 1926Great Britain.

RONALD FELDBAUM, Primary Examiner.

US. Cl. X.R. 66-1S4

